[ https://issues.apache.org/jira/browse/HBASE-26274?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Tak-Lon (Stephen) Wu resolved HBASE-26274. ------------------------------------------ Resolution: Fixed > Create an option to reintroduce BlockCache to mapreduce job > ----------------------------------------------------------- > > Key: HBASE-26274 > URL: https://issues.apache.org/jira/browse/HBASE-26274 > Project: HBase > Issue Type: Bug > Components: BlockCache, HFile, mapreduce > Affects Versions: 3.0.0-alpha-1, 2.4.6 > Reporter: Tak-Lon (Stephen) Wu > Assignee: Tak-Lon (Stephen) Wu > Priority: Major > Fix For: 2.5.0, 2.3.7, 2.4.7, 3.0.0-alpha-1 > > > In HBASE-21498 (see [this > commit|https://github.com/apache/hbase/commit/27a0f205c52f83fe7500ee2ffc6cf6582f565a63#diff-8a3e39e6df1afe47811fc17702da598fe0d80496d66e579bea4bd224c6d8da03R218], > it change the behavior that only region server can initialize on-heap > BlockCache/LruBlockCache, this should be the right change for HMaster. > Other downstream dependency that uses getScanner from a file-based region and > read HStore/HFile lost the BlockCache for caching INDEX/LEAF_INDEX (at least > still a problem with HBase-2.4) after this change (it worked before) and > caused performance impact with 2x slower. > One way to bring back the performance is to allow non-RS and non-HMaster can > use a compact version of blockcache with smaller memory and less hbase > internal configuration. > Or if we can find a way to cache or skip reading the same {{LEAF_INDEX}} when > scanning the DATA block with HFile. -- This message was sent by Atlassian Jira (v8.3.4#803005)